Device for viewing oil well bore hole



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DEVICE FOR VIEWING OIL WELL BORE HOLE Filed Feb. 3, 1956- l1 Sheets-Sheet 5 /l-rTa-RNEy.

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JAMES Moo/v ROBERT Cf woxe Elfi -l ATTaRA/Lw Nov. 10, 1959 J. MooN ErAL 2,912,495 v DEVICE FOR VIEWING oIL WELL BoRE HOLE Filed Feb. s. 1956 11 sheets-Sheet 7 .inve/Vraies.

Nov. 10, 1959 J. MOON ETAL DEvIcE EOE VIEWING oIL WELL EoRE HOLE Filed Feb. 5, 1956 v Nav. 1o, 1959 J, MOON HAL y y2,912,495

DEVICE FOR VIEWING OIL WELL BORE HOLE Filed Feb. 3, 1956 l1 Sheets-Sheet 10 Imis/vrom 17A/nfs Moon d Ramr [kou/ 5 IEW/WMM Nov. 10, 1959 J. MooN EIAL DEvIcE EoR VIEWING oIL WELL EoRE HOLE 11 Sheets-Sheet 11v Filed Feb. 3, 1956 I. s. n Gm 7 R 0 .M m w 2 0 0. v 1 3 T u 1 NC m m1 Fm m N n RM lon .1 5. fu' E' 0 wh E R VM .|.|||||l||l .M Ll 6 0 m mm o 0| I m m M IP AIMF l cu VM nV v .m E I` n NB v HN m. n J U Tw 140 IIZIII.. o.. Nr mf KP MMC ZKM D u amm mmm VM I amm Hun P m ,an n ...m mm k R C: .WL um Mm-m mw nm. EM 5 MM A VH Mm. .JC E mm w BH 7 LN .R 2 mw u d F III' l Il E mm L nw ww EN Ho ou vn Pc Ps r A: GR R INKL TM am KI NT. y Sf- NL HN AE RW A Hu HU ma" PW PD HTTORNE y.

lUnited States Pater 2,912,495 DEVICE FOR VIEWING OIL WELL BORE HOLE James Moon, Santa Ana, and Robert C. Crooke, Temple City, Calif. Application February 3, 1956, serial No. 563,344 2s' Claims. (Cl. 17a-16.8)

This invention relates to novel apparatus for visually observing the condition vof well bores and is particularly concerned 'with a device of this character embodying a closed circuit television system for viewing from a remote distance the inside 'of an oil well bore or casing.

Devices have heretofore been developed for subterranian and submarine photography, but such devices have not generally proved very successful for observing a well bore, or Vwell casings, well drilling tools and the like in a well bore, mostly due to the difficult conditions of high pressures land temperatures encountered at great depths in an oil well bore, and the drilling mud, oil land -muddy water common to such an environment. Particularly, while a device which would permit proper visual inspection of a well bore hole from the well'surface would be of considerable advantage lto the -industry, no commercially satisfactory device known to applicants has heretofore been rdeveloped which enables visualization of a well bore from 'remote distances while the tool is in 'the well bore.

One object of the invention is to design a device permitting viewing ofthe inside of a well bore.

Another object is the design of such Va device incorporating a lcamera and preferably a television system for viewing a well bore from a station at the surface of the well.

A still further object is to 'design a tool which can be submerged in an oil well bore at great depths and in con- .'tact with well bore fluids, yet which permits pictorial vviewing 'of the well bore even in the presence of and durpassage of the tool through relatively opaque liquids in lthe well bore. By the term pictorial viewing is meant the taking of photographs fby means of a film-containing camera, or the use of a television camera for direct transmission of apictur'e to a station at the vsurface of the well bore.

Another Iobject is the design 'of a tool for pictorially viewing a well bore, which 'includes camera means and has provision for 'cooling to maintain the vcamera means .at a proper "operating temperature under high well bore temperatures, and for efficiently scanning and lighting vthe portion 'of the well bore under observation. 4 Yet another object is `the provision of a tool for viewing ,-'a well bore, which includes 'camera vmeans and a protec- ;tive lens, in conjunction with ta -`closure means and lens Awashing means, the closure means being ladapted to be ,opened and closed afplurality of times to permit washing of the lens at selected 'intervals while the Ltool is in the -well bore, so that a lnumber of pictures may be `obtained 4at various locations within the well bore without removal lof the tool from the bore.

A particular object is to provide Va device for vremote ypictorial visualization of an oil 'well bore hole, said device being constructed of a combination of readily avail- -able structural, optical, and television receiving and transmitting components, `which can be assembled-"to form va compact, rugged, yet reliable instrument for `the above purpose, able to withstand and 4operate under the yunusual environmental conditions, including the high pres'- ,sures-, temperatures and opaque 'and viscous liquids generally encountered in oil well bores.

2 Qther objects and advantages 'will appear hereinafter. The device of the invention is specially designed for vand embodies camera means preferably as a component of a closed circuit television system which is of standard commercial type except that tie television package embodying all of the electronic and optical components thereof, is altered in shape, eg. to an elongated cylindrical form, to permit its being housed within the relatively fslender elongated case of our instrument. In order for the v'electronic and optical components of the system to 'function properly, provision is made to isolate these cornponents from the environmental conditions, c g. the high `temperatures and pressures, found in oil well bores. Particularly, the instrument hereof is designed to withstand Yhydrostatic well pressures in excess of 6,000 p.s.i. and ambient wL ll temperatures, 'e.g. upto and above 375 F., land meansare provided to protect the viewing lens from lbecoming coated with luid which render it optically opaque, and to wash the viewing lens free of any dirt or soil which is deposited thereon. The system is also provided with means for supplying adequate-illumination to the subject matter which is to be viewed, and the instrument also 'embodies means for maintaining the .sensitive electronic components of the television system suilciently lcool to insure its 'eilicie'nt operation.

In one form of the invention lthe outer case of the .tool or Ainstruirent is of cylindrical shape and is composed of severaly components which are joined together ,for yease of manufacture and assembly. At the lower end of the cylinder cas'e (the viewing end) there is provided a closure means, preferably a ilexible diaphragm which can be opened and closed, land above this is positioned a protectivevie'wiiig lens which closes off the interior of the case from lWell bore iluids, and through which the ytelevision camera receives light. The protective lens' is ,suthci'ently thick to withstand the pressure of the well `bore fluids, and means is provided to afford a pressure seal between the lens and case. The purpose of the closure or the diaphragm is to protect the protective viewing `lens when the unit is .passing through fluids which would Acoatthe outer surface of the protective lens. Between thejd'iaphragm and the protective lens is a chamber into which va lens washing iluid can be forced by means of a "conduit communicating with the chamber, lsaid fluid being discharged directly below and closely adjacent the surface of the lens. y

Immediately above the protective' lens, andsurroundting the camera lens is a light source preferably in the shape of a doughnut. Above this and centered in the instrument case is the packaged electronic equipment, including the camera, of the television system. The annular space between the electronic equipment housing vand the 'outer' shell of the instrument case is filled with a cooling medium such as a refrigerated eutectic material which will'absorb the heat generated in the system and that received from the oil well bore. u Above the electronic equipment is a pressure equalized hydraulic system including a cylinder, piston, porting, and drive motor, all of which operate the diaphragm moved downward the fluid is forced vout of `a port and through the conduit, causing the ilexible diaphragm to eXpand When the direction 'of motion Vof the piston is reversed, the tluid returns to the resulting low pressure .retreated Nea. io, 195ev .bt area below the piston. The upper portion of the hydraulic cylinder is connected through piping to a check valve and thence through a second conduit to the protective lens washing chamber. The upper portion of the hydraulic cylinder is also connected through piping and a check valve to the bottom portion of the reservoir, which contains a freely oating piston with the space above the piston vented to the well bore fluid and pressure. As the hydraulic piston is moved upwards the washing fluid is forced out the top of the hydraulic cylinder through the protective lens washing system. The washing fluid cannot re-enter the reservoir due to the presence of the last mentioned check valve. When the hydraulic piston is displaced downward again, fluid enters the top portion of the hydraulic cylinder from the reservoir. Well bore uid cannot be taken from below the protective lens into the hydraulic cylinder through the wash fluid piping due to the presence of the check valve in such piping. The hydraulic piston is moved by means of a threaded piston rod running in a drive nut which is connected to a motor.

At the top of the instrument is a packing system through which an electrical cable enters the case, and an arrangement for tying the cable armor onto the case for supporting the instrument and for raising and lowering it in a well bore. The electrical cable carries the necessary electrical conductors to supply energy to the various electrical or electronic components of the system, i.e. the lamp, television circuit and motor. The cable is covered on the outside with armor' wire which will carry the load and protect the cable.

The entire inside of the tool is charged with an inert gas at slightly more than atmospheric pressure. The use of the inert gas avoids the problems associated with air when temperature changes take place, due to Water vapor in the air.

From the above it is seen that on actuation of the television system having a viewing station at the Well surface, a picture of the well bore at any level of the bore can be obtained and the condition of the bore thus ascertained. If the protective viewing lens becomes covered with mud or soil particles so that the picture is unclear, the motor can be actuated to force cleaning fluid preferably of transparent type, from the hydraulic cylinder and over the lens to clear it. Should the instrument pass through sticky or opaque fluids, the motor can be actuated in the opposite direction to force fluid into the protective diaphragm to close olf well bore fluids from contact with the protective viewing lens, and when the well bore is to be viewed under these conditions, the diaphragm can be opened and the transparent cleaning fluid located in the space in front of the protective viewing lens permits viewing of a portion of Ithe bore through the transparent liquid.

In the embodiment of the invention noted above, the system is arranged to enable the well bore directly below the instrument to be viewed, while in another embodiment, described more fully hereinafter, the system is especially arranged to enable viewing of the sides of a well bore.

The invention will be more readily understood from the following description of certain preferred embodiments taken in connection with the accompanying drawings wherein:

Fig. 1 is a cross sectional elevation of our assembled device, certain parts being shown in full for clarity;

Fig. 2 is an enlarged sectional elevation of the bottom portion of the device of Fig. 1, with the lens protecting diaphragm open and certain parts being shown in full for clarity;

Fig. 3 is another enlarged sectional elevation of the bottom portion of the device of Fig. 1, with the lens protecting diaphragm closed and most of the internal parts shown in elevation for clarity;

Fig. 4 is a section taken on line 4 4 of Fig. 2;

Fig. 5 is a section taken on line 5 5 of Fig. 2;

Fig. 6 is a section taken on line 6 6 of Fig. 2;

Fig. 7 is a bottom plan view taken on line 7 7 of Fig. 2;

Fig. 8 is a section taken on line 8 8 of Fig. 2;

Fig. 9 is a sectional View of the outer portion of the protective lens;

Fig. 10 is an elevation of the inner portion of the protective lens;

Fig. 11 is an enlarged sectional view of a portion of the device of Fig. 1 directly above the bottom portion shown in Fig. 2;

Fig. 12 is a section taken on line 12 12 of Fig. 11;

Fig. 13 is a section taken on line 13-13 of Fig. 11;

Fig. 14 is an enlarged sectional view of that portion of the device of Fig. 1 directly above the portion shown in Fig. l1;

Fig. 15 is a section taken on line 15-15 of Fig. 14;

Fig. 16 is a section taken on line 16 16 of Fig. 14;

Fig. 17 is a section taken on line 17-17 of Fig. 14;

Fig. 18 is an enlarged sectional elevation of that portion of the device of Fig. 1 directly above the portion shown in Fig. 14;

Fig. 19 is a section taken on line 19-19 of Fig. 18;

Fig. 20 is a section taken on line 20 20 of Fig. 18;

Fig. 21 is a section taken on line 21-21 of Fig. 18;

Fig. 22 is an enlarged sectional elevation of that portion of the device of Fig. 1 directly above the portion shown in Fig. 18;

Fig. 23 is a section taken on line 23 23 of Fig. 22;

Fig. 24 is a section taken on line 24 24 of Fig. 22;

Fig. 25 is an irregular section taken on line 25 25 of Fig. 22;

Fig. 26 is a sectional elevation of a modification of the bottom portion of the device containing the optical viewing system;

Fig. 27 is a section taken on line 27 27 of Fig. 26;

Fig. 28 is a section taken on line 28-28 of Fig. 26;

Fig. 29 is a section taken on line 29-29 of Fig. 26;

Fig. 30 is a section taken on line 30-30 of Fig. 26;

Fig. 3l is a section taken on line 31 31 of Fig. 2; and

Fig. 32 is a schematic diagram of a typical commercial closed circuit television system which can be employed in our device.

Referring to Fig. 1, the device comprises an elongated cylindrical housing 33 made up of a series of cylindrical sections threadably joined to each other, the housing having positioned in the lower end thereof an optical viewing system 34, including a protective lens 35 and a lens protective diaphragm 37 (see Fig. 2), and a television camera and transmitting system 36, these components cooperating in the manner described below for viewing a bore hole. Within housing 33 and located above the television system 36 is a hydraulic system 38 which serves to provide fluid for and to actuate a washing system for the protective lens, and also to operate the protective diaphragm 37. A motor 4l) and associated linking mechanism 41 between the motor and hydraulic system 38, are located within housing 33 above the hydraulic system 38 for operating the latter, and in the upper portion of the device above the motor is positioned a reservoir 42 which supplies makeup fluid to the hydraulic system 38. The device is suspended on an armored cable 44 for lowering and raising the device in a Well bore hole, the cable extending out through the top of the device and containing electrical leads for purposes pointed out more fully below.

Turning now particularly to Fig. 2 at the lower end of the device is a closure ring assembly 46 made up of a cylindrical shell 48 the outside surface of which is grooved at 5i). Through the shell and passing into the groove are several holes 52 (see also Fig. 8). To the inner surface of the shell 48 is vulvanized adjacent its upper and lower edges 55 the cylindrical flexible diaphragm 37 made of a suitable elastic material such as rubber. The diaphragm 37 when deated is shown in Fig. 2, with a small annular space" between the shell 48 and the diaphragm, but when inflated' by means of pressure fluid, distends into the chamber 72, forming a doughnut-shaped member closed at its center, as seen in Fig. 3, thus closing otf the space or chamber 72 between the diaphragm 37 and lens 35. The closure ring assembly 46, including diaphragm 37, is slipped inside of a retainer ring 58 so that assembly 46 fits at its upper end inside of an annular slot S4 provided in the inner surface of retainer ring 58. The lower end of 4ring 58 has an internal thread 60 into which a retainer'nutV 62 can be screwed for the purpose of securely holding the closure ring assembly 46 in the retainer ring 58, the' nut 62 having an annular groove 57 to accommodatethe lower end of shell 48 and' diaphragm 37 connected thereto. The retainer ring, 58 is supplied at its upper end with an external thread system, such as the two step thread 64 shown, for the purpose of joining 58 tothe lamp housing body portion 66.

The retainer ring 58 is drilledl with two bores 68 and 70. One of the bores 68 is directed radially inward at 69 and is the outlet for the protective lens wash fluid, communicating with chamber 72 dened by retainer ring 58, diaphragm 37 and the frontv of the protective lens 35'. While only one discharge outlet 69' is shown, a plurality of such outlets can be provided about the periphery and 'adjacent the lower surface 35' of lens 35. The other bore 70 is drilled so that it registers with the groove 59 in the shell 48 and is for the purpose of introducing iluid into the space 71 between the diaphragm andV shell 48 of ring 46, to inflate the flexible diaphragm. Both of these bores or conduits terminate at their upper ends in the blocked annulus 74 at the step in the thread system 64 (see also Fig. 3l). This provides aseparate arcuate channel 75 which communicates with bore 68, and a separate arcuate channel 76 communicating with bore 70. The annulus 74 is blocked in the above manner by lats 77 at diametrically opposite portions of annulus 74, in order to prevent the mixing ofthe fluids in the lens washing and diaphragm actuating' systems, as will be seen more clearly hereinafter. The retainer ring 58 is provided with a shoulder 78 which, along with a gasket 100, holds the protective lens 35 in position in the lamp housingy body 66.

VThe protective lens 35 is designed thick enough to withstand the external pressure against its front surface 35. The surface 35 of the lens has a convex shape for the purpose of facilitating the washing action of the lens washing tluid. The lens is made up of two pieces of suit-able glass, a central tapered portion 82 in the form of a truncated cone, and an outer hollow cylindrical portion 84 internally tapered at 83 to tit the taper of outer portion S2 (see Figs. 9 and l0). The two portions 82 and 84of the lens 35 are matingly cemented together by means of a black opaque cement 85. This arrangement of the protective lens 35 eliminates the tendency towards backscattering of light to the optical lens of the television system when a film of particles is deposited on the front surface 35 protective lens 35.

The lamp housing body 66 is threaded at both ends 86 and 88. The lower end makes up with the retainer ring- 58, and the upper end makes up with the body shell 90'surrounding the housing 92 containing a television'camera indicated by the numeral 93 and the electronic television components. A cylindrical housing 94 containing a conventional television camera lens (not shown) is axially connected to the lower end of television housing 92, in axial alignment with lens 35, and

may be obtained in the smallestspace. It is noted that lamp 98 is positioned directly opposite the outer portion 84 of lens 315. In this manner lightv is directed from the lamp through outer portion 84 of the lens into the well bore beyond' the lower endy of ring 46, as indicated by arrows A in Fig. 2, and the light is reected back from the-well bore through the centralv portion 82 of lens 35 into the camera lens-containingcylinder 94 of the television system, as indicated by arrows B in Fig. 2. The opaque iilm 85 prevents passage of light from outer portion 82 thereof.

An O ring groove 99 is formed in lamp housing 66, and into this groove is positionedthe O ring 100 for the purpose of forming la pressure tight seal between the protective lens 35 andthe lamp housing body 66. The lamp housing body 66 also contains two circular seats 102 and 104- against which the protective` lens 35 is Vheld by the'reta-iner ring 58. A pair of bores 68 and 78 are drilled into lamp body 66, these bores corresponding to the bores 68 and 7), respectively, drilled in retainer ring 58. The lower ends of bores 68. and 70 terminate at the blocked `annulus 74 between the step threads 64, and communicate with channels 75 and 76, respectively.l Hence, bores 68 and 68' and channel 75 form a continuous conduit 106 and bores 70, 70v and channel 76 forms a separate continuous conduit 108. The upper ends of bores 68' and 70" terminate in drilled and threaded holes 109 and 110 which take the elbows 112 lens portion 84 of lens 35 directly into the center lens and 114. A diaphragmclosure tube 116 is fastened to the elbow 114 and a lens washing tube 115 is fastened toy the elbow 112. Y

The upper end of the lamp housing body 66 is provided with a shoulder 118 upon which a stop ring 120 is seated. Stop ring 120 is provided for the purpose of supporting the television camera and electronics package retained in housing952. Ring l120 is drilled with holes which allow for passage of the lamp wires 122, the diaphragm closure tube 1,16 and the lens washing tube 115. The body shell 90 is provided with threads 124 and 126 at opposite ends. The lower thread 124 adapted to receive light passing through the central portion82 only of lens 35.

The-lamp housing body 66 contains a llamp housing 95 in'which is formed an annular recess 96 in which a doughnut-shaped lamp 98 s positioned'by means of fasteners 101- connecting the lamp to a bracket 103 attached to the lamp' housing (see Fig'. 6'). The lamp V98 is of doughnut makes up with the lamp housing body 66, thread 126 makes up with ya body shellv 128.

The television camera and electronics case 92, including cameralens holder 94, contains all lof the necessary electronic and optical components of a complete closed circuit vidicon television system. The television' system employed, including the transmitting andy vrece1ving components thereoff is of la conventional coinmer'c'ial' type available from sourcessuch as Radio Corl poration of America. Fig. 32 shows for purposes of illustration a schematic diagram of the main components of a typical rtelevision system which we can employ in our device. This system per se is not claimed as a part of our invention. All of the components illustrated in' Fig. 32 are contained within the electronics case 92 of Fig. 2, except the viewing or picture tube 123 and an outside power supply 125, which are located at the surface and connected to the electronics case 92 bymeansof leads 127.. This system is shown on page 2 of the Radio Corporation of `America brochure for Model ITV-6, Industrial Television Equipment. The diameter of the electronic shell orhousingv 92 is maintained as small as possible in keeping with good electronic design.

In any case, the diameter of the electronic package 921l is kept smaller thanY the inside diameter of the outer body shell 90.

The'space 129 `between thetelevision-camera and electronics case 92, and the body shell is substantially and the upper y The spaceA between adjacent and portions of containers 130 is employed for the; passage of the hydraulic lines and 116 and lamp` wires 122. The containers 130 are filled with a commercially available and suitable coolant, preferably a eutectic substance, e.g. one composed of a mixture of calcium chloride, starch, and water. The heat capacity and volume of the eutectic material is so chosen that the complete tool when cooled to 20 F. at the start of any operation will only reach a temperature of 120 F. at the photosensitive surface of the vidicon tube after an exposure of four hours to an outside ambient temperature of 375 F.

The longitudinal motion of the television camera and electronics package 92 is limited at the upper end by the keeper rings 132 and 134. These keeper rings are held against the case 92 by the abutting lower end 136 ofthe upper adjacent body shell 128.

The body shell 128 (see Figs. 2 and 11) is provided with a right hand thread system 136 on its lower end, and a left hand thread system 137 on its other end. This permits the lower sections 128, 98, 66 and 58 of the system to be joined to the upper body shell 138 without relative rotation of either section 90 or 138 at opposite ends of section 128.

The body shell 138 is likewise provided with a thread system on each end, the lower threads 1441 for making up with the body shell 128, the upper threads 142 for making up with body shell 144 (see also Fig. 14). The body shell 138 is drilled and tapped to take the dog pointed socket head set screw 146 which holds a sleeve 148 positioned in body shell 138 from moving.

A base ring 150 (see Fig. 11) is provided as an anchor plate for the hydraulic system indicated generally by numeral 38. The base ring 150 is held in place by the shoulder 154 provided on the body shell 128, and is prevented from rotating by means of a serrated edge 156 thereon (see Fig. 13). Base ring 150 is drilled with clearance holes to receive the keeper bolts 158, for the elbow 164i which is connected to the hydraulic diaphragm closure line 116, for the electrical cable 44 carrying lamp wires 122 and television leads 127 (see also Fig. 2), and for the hydraulic wash line 115. The keeper bolts 158 are for the purpose of anchoring the cylinder base 164 to the base ring 150.

The cylinder base 164 is threaded internally at 166 and is provided with an O ring groove 168 to accommodate O ring 170. The cylinder 172 is screwed into the base 164 making a pressure tight seal with O ring 170. Cylinder base 164 has a port 174 for discharging iiuid via line 116 to the flexible diaphragm 37. The hydraulic cylinder 172 is provided with a piston 178 which makes a pressure tight seal With the cylinder walls by means the cup ring seals 180. The arrangement is such that the seal is maintained when the piston moves in either direction. The upper end of the cylinder 172 is mated by a thread system 182 and O ring seal 184 to cylinder top member 186.

The cylinder top 186 is drilled and provided with packing 188 to take the piston rod 198 which is connected to the piston 178 by means of the piston rod nut 192. The cylinder top 186 is also drilled to provide a hydraulic port 194 to which the T iitting 196 is connected. One arm 195 of the T 196 is connected to the lens washing tube 115 which contains a ball check valve 198 (see Fig. 2) permitting flow only in a direction through wash line 115 away from the T toward the lens washing bores 68 and `68. The other arm 288 of the T 196 is con nected to a hydraulic charging line 202 which contains a ball check valve 284 (see Fig. 14), and is connected to the lower end of the reservoir 42. The check valve 204 permits uid flow only from the reservoir to the hydraulic cylinder 172.

The hydraulic cylinder assembly 38 is held in place by the ring 286 and the sleeve 148, which is forced up against the keeper ring 208 (see Fig. 14). The sleeve 148 which is restrained from rotating by set screw 146, has a fork member 209 thereon which receives the upper end of the piston rod 190. Sleeve 148 has a tendency to rotate because fork 209 on the sleeve functions to restrain the rotational motion of the piston rod in the manner described below. The piston rod 190 above the hydraulic cylinder 38 has a length of flats indicated at 210 and a length of threads 212. The length of flats and threads are each at least equal to that of the travel of piston 178, permitting piston 178 to travel from the bottom to the top of hydraulic cylinder 38. The section of ats 210 having a polygonal cross section passes through a mating polygonal aperture 211 (see Fig. 16) in the fork 209, which limits the piston rod 190 and piston 178 to reciprocal movement only when the motor drive nut 214 engaging the threaded portion 212 of the piston rod 198. is rotated.

An electric motor and gear unit indicated generally by numeral 40 tits inside of the body shell 144, the unit being iixed to an anchor plate 218, welded at 221 inside the shell 144 near the top thereof, by means of retainer bolts 220. Motor shaft 217 passes through the keeper ring 208, and is connected by means of taper bolts 219 to the drive nut 214. The anchor plate 218 is drilled to provide openings for the motor electric power lines 222, which are taken out of the main cable 44, at the junction box 224. The main cable 44 carries the lamp leads 122, the television leads 127 and the motor leads 222, said leads being contained in separate control cables 122', 127 and 222', respectively. Access through the anchor plate 218 is also provided for the main cable 44 and hydraulic charging line 202. The lower end of the motor and gear units are positioned by the keeper ring 208 and the keeper sleeve 148. The body shell 144 is joined to the body shell 226 (see also Fig. 18) by means of the make-up shell 225 which has a right hand and left hand thread system 228 and 231B to permit shell 144 to be connected to shell 226 Without relative rotation.

The motor and gear unit 48 are connected by leads 222 to a cycle timer (not shown) at a station at the surface of the Well, said timer operating to cut the motor when the hydraulic piston 178 reaches the top or bottom of hydraulic cylinder 38. Such timer is also operative to cause a reciprocating motion of piston 178 through a relatively small distance in the cylinder 38, for a purpose noted hereinafter. Cycle timers of this type are Well known and commercially available. A typical cycle timer which can be used in the invention is the model type 520 cycle timer marketed by the P. W. Cramer Company of Centerbrook, Connecticut, and shown in its bulletin P.B. 510.

Referring now to Fig. 18, cylindrical reservoir body 42 is closed on the lower end by the reservoir base bottom 234 and on the top by the reservoir top member 236. These end members are internally threaded at 238 to mate with external threads at the ends of the reservoir cylinder 42. O ring seals 240 are positioned between the end members 234 and 236, and the opposite ends of cylinder 42. Inside the reservoir 42 is a freely moving piston 242. This piston carries ring seals 243 to make a pressure tight seal with the walls of cylinder 42, and divides the reservoir into two chambers with the protective lens wash fluid maintained in chamber 244 below the piston 242. The chamber 246 above the piston is filled with the well bore fluid at ambient pressure by` means of the vent plug 248 communicating with chamber 246 via conduit 250.

The reservoir cylinder ends 234 and 236 carry trunnions 252 and 254 which are axially bored to match bores formed in cylinder ends 234 and 236, and forming conduits 256 and 250. The lower trunnion 252 fits into a recess 258 formed in a journal bearing 268 integral with the body shell 226, and an O ring seal 268 is provided between the trunnion 252 and bearing 268. The lower journal bearing is bored at 261 to match the conduit 256. This gives a pressure tight joint which is rotatable for purposes of making up the tool, and which provides the lower journal bearing 260 is a cross connection-267l from bore 261 to'an outsidefill-up plug 269A to permit charging of the hydraulic washing Huid to the lower chamber of reservoir 42. T he trunnion 2541on the-reser Voir top member 236 tits into a recess 262 formedin aVl journal bearing 264 rintegral with the upper adjacentbodyshellv 266, and an O ring seal 270 is providedv between the -trunnion 254 and the bearing 264. This journal bear'- ing is drilled at 271 to. match the trunnion portv272,

forming conduit 25.0, which terminates at onef end withthe vent plug 248 and at its other end with the upper chamber 246 of the reservoir. Body shells 22.61and-266v are -joined by means of. a thread system indicated at 274.?

Referring to Fig. 22, the body shell 266, while furnishingy journal 264 for the reservoir andan inert gas charging plug 276, functions chiefly for the purpose of'v sealing and tying off the armored electrical cable 44 carry ing motor leads 222, television leads 7127 andllampleads-` 122. The cable 44 enters the tool at the eXtreme-top, where it is passed through a clearance hole-.278i in the head 280 of the instrument case. The outerarmor wire 2.82 around the cable is peeled back at 284 and-.cutoff so that the required length of unarmored cable can be run down through the tool to its juncture with an upper:

housing 286 (see Fig. 2) connected to television case. 92. The cutoff ends 288 of the armor are bent back so that they will iit in behind an armor wire retaining slip 290, which is wedged and locked in place by means of a locking nut 291 which mates with threads 287 on a depending cylinder portion 289 of head 280. Below the armor, or load transfer point, the unarmored cable passes through a high pressure packing gland system 292 consisting of chevron ring packing293, a lantern ring 294 interposed between layers of the chevron ring packing, a standard packing ring 295 anda keeper nut 296 mating with the threads 297' on a flange 297 extending upwardly from a housing 298 integral with body shell 266, and which contains an annular recess 299 which carries the chevron packing 293 and the lantern ring 294.

Operation of the device described above is asfollows: The retainer nut 62 at the lower end of the tool is removed and the closure ring assembly 46 including the diaphragm 37 is withdrawn. The motor 40 is actuated to cause the piston 178 to move to the upper endV of hydraulic cylinder 38, following which the entire tool is inverted and a uid, which may be the same as the washing liuid described below or any other suitablefluid, is introduced into the end of bore 70' adjacent chamber 72, the fluid being conducted by gravity'via bore 70, channel 76, bore 70 and line 116 into the chamber 301 of hydraulic cylinder 38. The closure ring assembly 46 is then inserted into retainer ring 58 and the nut 62 is screwed into position to lock the closure ring assembly 46 in the lower end of the tool. The fluid in the lowerchamber 301 of the hydraulic cylinder is now sealed therein, since this chamber forms a closed fluid system with the diaphragm closure line 116, and space, 71 between diaphragm 37 and the adjacent shell 48.

The amount of Huid thus introduced in the closed system including the lower chamber 301 of the hydraulic cylinder 38, line116, bores and 70', and space 71, is such that when piston 178 is in its lowermost position in cylinder 38, as viewed in Fig. l1, the diaphragm 37. will be inflated and expanded to its fully closed position as shown in Fig. 3, and when the piston 178'is in its uppermost position at the top of cylinder 38 the diaphragm 37 will lue-substantially open as shown in Fig. 2.

With the instrument still inverted, a washing fluid,

which may be an alcohol, a glycol, a hydrocarbon or'v chlorinated hydrocarbon solvent, water, or any other suitable preferably transparent lens washing fluid, is introduced into the lower chamber 244 of the reservoir cylinder 42. Charging f'they tool:r with washing fluidi idf accomplishedfby removing plug 269 and-introducing the cylinder 38. During this procedure the tool is gentlyy rocked back and forth to purge any air. in liney 202 through the conduit 267 and the' filling opening 269lI When lling of` the instrument with washing fluid has been' accomplished the plug 269' is screwed into position as seen in Fig. 18.

Itwill be noted that during thefrlling operation dei scribed "above, washing fluid rapidly passes from the fil-ling,

conduit 267 through' line 202v and through the check valve 204 to the hydraulic cylinder 3.8, since check valve. 204 is designed so thatonly a relatively small fluid pressure is required for passage of liqfuid' therethrough in a downward direction asv viewed in, Fig. 14. However, it will'be noted that during the lilling` operation while the washing fluid lls line between T 196 and the check valver198, the fluid, does not pass the lattervcheck valve since this valve is spring loaded and preferably designed to` permit'passage of fluid downwardly as seen in Fig. 2, at-aftluid pressure ofv 25 p.s.i. or greater.

The instrument isv then lowered into the bore hole. Preferably, at the commencement of lowering of the tool into the bore, or prior thereto, the motor 4t) is actuated to.

cause hydraulic piston 178 to travel to the bottom of. the cylinder 38 as viewed in Fig. l'l. This forces hydraulical fluid out of the lower chamber 391 of the hydraulic'cylinder, through elbow 160, line 116, bores 70, and 70, and-holes 52; into the space '71 between the diaphragm 37 and the shell 48. This causes the diaphragm to expand until it closes off chamberf 72 from the bore hole belowv the diaphragm, as seen in Fig. 3. During.,

movement of-piston 178 downward in cylinder 38, the pressure in the upper chamber 36,8 of the hydraulic cylinder drops, causing piston 242 in the reservoir cylinder 42 to move downward and to force fluid into the upper chamber 300 oftheihydraulic cylinder, via line 282' and valve 204 as described'above, since the upper chamber, 246 ofthe reservoir is at ahigher'pressure corresponding to the hydrostatic or well borepressure due to the presence of vent plug- 248.

When it is desiredto View the bore hole at any particularL depth, the'instrument is lowered to this point, and the circuits to the lamp and television power sources are actuated from a station at thesurface of the bore, at which stationV the television picture tube which receives` the imf means, e.g. measuring the length of cable lowered. If

the fluid through which the tool is passed isl relatively clear fluid, the diaphragm 37 'canbe opened for purposey of. viewing ythe wellbore beneath, byactuating-the circuit to the motor 40 to cause the drive nut 214 to rotatein a direction toforce piston rod and-the piston 178 upward in hydraulic cylinder-38.

This operation simultaneously forceswashinguid out Vof the chamber 3001of thehydra-ulic cylinder, through bore 194, T 196,- T armf 195,` tube 1115; check valve. 198, and bores-68! and: 68;.into the chamber '72, in which-the uid' is introduced from.the1inclined`end 69 of' bore 68, which directsthefluid across the outer surface 315-t of the protective lens 35. cannotz circulate fromupper `chamber 300 -of the hydraulic cylinder back througlline;.202f tothe reservoir'f42, due to theI check valve 204; preventingy flow in this direction;Y Thefllidin'fchamberf72'g below lens 35, in) addition to cleaningthe surface 35"thereof,4 also serves asa transfA age of the well` bore tobe inspected, is also located. The' depth can; be; determined by any known or convenient It is noted that washing fluidi' ritil parent medium through which the desired area of the Well bore can be viewed, and such uid is prevented from returning from chamber 72 through line 115 back to the upper chamber 301) of the hydraulic cylinder, due to the action of check valve 198, which blocks flow in this direction.

Should the surface 35' of lens 35 become covered with oil, mud particles or other opaque material, resulting from passage of the instrument through opaque, murky or oily masses of liquid in the well bore, thus preventing a clear picture of the bore, or if the fluid in the well bore at which the picture is to be taken is opaque, instead of opening the diaphragm 37 relatively rapidly as described above, motor 4i) is actuated to lift piston 178 in the hydraulic cylinder 33 a relatively short distance, say about 2 inches otf the bottom of cylinder 38. The piston is then reciprocated up and down over a distance of about l inch to open the diaphragm slightly and then partially close the same, to produce a nozzle eiect and force washing iiuid in short jets into the space 72 below the lens while permitting opaque fluid in space 72 to be discharged through the opening in the diaphragm into the well bore below, thus eventually forming a clear bubble of liquid in space 72 between the diaphragm and lens 35. Thereafter the motor is actuated to force the hydraulic piston 178 to the top of the cylinder to completely open the diaphragm 37 to permit viewing of the well bore below through the bubble of washing liquid in space 72. Particularly if the washing uid is lighter than the iiuid in the well bore, the bubble of washing iiuid will be maintained in space 72 for a period suiicient to permit proper viewing of the well bore at the desired location therein. After viewing the well bore, the motor can be actuated to force piston 178 downward to the bottom of cylinder 38, thus again closing the diaphragm 37.

r[he above described operations can be accomplished by means of a cycle timer, mentioned above, in series with the motor 40. The timer operates on a time relay such that at the time of reversal of the motor when piston 178 reaches the bottom or the top of the hydraulic cylinder, the motor will be cut oft to prevent further movement of the piston. Also the cycle timer can be set so that starting at any position of the piston 178 in the cylinder 38, say about 2 inches from the bottom of the cylinder, the cycle timer will stop the motion of the piston after it has traveled a certain distance, say downward about l inch to partly close the diaphragm 37, and then will reverse the motor to permit the piston to travel in the opposite direction, e.g. upward, to its initial starting position, to partially open the diaphragm, the cycle timer actuating the motor to repeat this operation so as to reciprocate piston 178 through a small predetermined distance above the bottom of cylinder 38, thus repeatedly partially opening and closing the diaphragm to produce a small but variable nozzle opening. Simultaneously with the opening and closing of the diaphragm this motion of piston 178 will cause a jetting action of the washing uid through bore 69 into space 72 below the lens 35, displacing the iiuid therein with clear Fluid while at the same time washing the surface 35 of the lens.

ln Figs. 26 to 30 is disclosed a modification of the device described above, the instant modification permitting viewing of the sides of a bore hole instead of a bore hole beneath the instrument, or in other words permitting the wall of the bore hole to be viewed at right angles to the axis of the hole. This embodiment is the same as that previously described, except that the structure at the end of the tool below the protective lens 35 is modified.

The modilication of the lower end of the television inspection tool as shown in Figs. 26 to 30, is basically composed of a cylindrical case 310, a cylindrical window 312, a sliding cylindrical window cover 314, a conical mirror 316, and a sliding cover operating mechanism indicated generally by numeral 313. This modified vend portion of our instrument is attached to the basic television inspection tool described above just below the protective lens 35.

The outside case 310 of the modified end portion hereof including a lens retainer cylinder 326, a housing 322 for a retractable shield actuating cylinder, and an end cap 324 threadably engaging housing 322 at 326. The lens retainer member 320 has its upper end provided with a thread system 323 which mates with threads on the lower end of the body member 66. rIhe lower end of member 326 is provided with a thread 33t) to make up with the upper end ot housing 322.

Positioned axially within lens retainer 32@ is a cylindrical light guard 332, having a diameter equal to that of the opaque joint S5 in protective lens 35 at the outside surface thereof. One end of the light guard 332 is placed against the lens 35 at 334, essentially coincident with the opaque joint 35 at the outside of the lens, the other end of the light guard being open at 336. The light guard 332 is maintained in position by three radial support bars 338 (see also Fig. 27).

In lens retainer member 320 is positioned the cylindrical window 312. Surrounding window 312 is an open portion 342 in member 326, the end portions 344 and 346 of member 3211 adjacent said open portion being connected by three narrow longitudinally extending segments 339, 341i and 341 (see Fig. 27) traversing open portion 342. One of the segments 339 contains a uid circulating bore 343 which at its upper end 349 connects with a bore 350 in end portion 344 of retainer member 326, bore 350 communicating with bore '7d' via the channel 76 or" the blocked annulus 7d (see Fig. 3l). The window area 312 is fitted with a transparent cylindrical window pane 352 which tits within the segments 339 to 341, and has an inside diameter equal to that of the inside diameter` of outer cylinder member 320. A series ot' spaced longitudinal bores 354 in member 3219 also communicate at their upper ends with bore 68 via channel in the blocked annulus 74, and at their lower end with annular space 342 between window 352 and the window cover 314.

A mirror 316 is mounted with its axis of revolution 356 coaxial with the axis of lens 35 and the cylinder 94 containing the optical lens of the television camera. From the apex 357 of the mirror 316 to a point 358 along its side, the element of the outer surface of the mirror is a straight line, forming a cone as indicated at 359, and below this point to the base of the mirror, the surface is generated by a convex curve, as indicated at 360. The television camera lens in cylinder 94 is focused on and receives light reiiected from the conical portion 359 of the mirror, while the convex portion 369 of the mirror 316 functions to reflect light passing through the outer portion 84 of lens 35 and between members 332 and 320, onto the bore hole wall, as indicated by arrows 362. The light which is reflected from the conical portion 359 of the mirror 316 into light guard 332 and portion S2 of lens 35, is received from the side of the bore hole through window 352, as indicated by arrows 363. Light guard 332 is provided to prevent interference between the light rays passing from the outer portion 84 of lens 35 to the convex portion 360 of mirror 316, and the light rays reflected back from the straight portion 359 of mirror 316 to the center portion S2 of lens 35.

The protective window 352 and the mirror 316 are held in place by a shoulder 364 in lens retainer member 329 and a shoulder 366 on the upper threaded end of housing 322. All of the space inside of lens retainer cylinder 320 and light guard 332, between the mirror 316 and the protective lens 35, is tilled with a suitable transparent liquid such as alcohol, which facilitates viewing of the side o the Well bore or casing outside of window 3152. The fluid pressure within member 320l ismaimA tained at the bore hole pressure by means of a porous.

plug-363 positioned in the body of member 320.

In order to protect the window 352 from being coated.

with opaque substances while passing through opaque uids, the retractable `cylindrical shield or cover 3141s provided. The shield 314- is seatedandsealed-by. G rings.

370 in spaced grooves formed in the outer surfacel of member 320, and is made retractable by connecting it-` toa lift yarm 372 which is connected toV the piston rod374; The space 342 of thehydrauliccylinder assembly 31S. l between the retractable shield 314 and the protective window 352 can be filled with a transparentwashlng'uid.

This is accomplished by means of the bores354 which at their upperends are connected via bore 68 to the.

lens washing tube 115 of the tool.

The cylindrical housing 3222 is provided with two diametrically aligned. guide slots 376-(see Fig. 28`). The guide slots allow the lift arm 372 to pass throfugh said housing to connect with the retractable shield 314. The piston! rod 374 to which the lift arm 372' is connected,

ing 322; A bore 390 in base member 382' connectsY the hydraulic cylinder 379 Via a ventl 392 with the annular space 391 between the outer cylinder 322: and hydraulic cylinder 379. Hence the lower side- 393 of piston378 is subject to the well bore pressure via slots 3.76, space 391, and bore 390, while the other side 394' of piston 3'78 is connected via elbowv 395, line 396, fitting 396 and iluid annulus 397, to the bore`348. The retractable shield 314 is maintained in the closed position shown in Fig. 26 by means of a spring 398l disposed about piston rod 374, the spring abfutting the upper` end 397 of hydraulic cylinder 379 and the lower side 397 of lift arm 372, urging the lift arm upward.

In order to retract the shield 314 to view a side of the well bore, piston 173 of hydraulic cylinder 33' is actuated downward as described above, causing a positive uid pressure with respect to bore holepressure to be exerted through line 116, bores '70', 350 and 348, and line'396 to the upper side 394 of the piston 378 in the lower hydraulic cylinder 379. This positive pressure will overcome the tension of spring 398. and the weil bore pressure exerted against the lower side 393 piston 378, causing piston378 to be displaced downward and retracting shield 314. This uncovers the protective window 352 for viewing the side of the bore hole. When the positive pressure. is released by actuating piston 178 of'hydraulic cylinder 38 in the opposite direction, i.e. upward as described above, the spring 398 urges the shield 314 again into closed position to cover the window 352; This upward movement of piston 178 forces wash iiuid out of chamber 39d` of the hydraulic cylinder 38, through tube 115, bores 68 and 354, and into space 342 between shield4 314 and window 352, to fill said space with washing tinid and to thus clean the outside of the window pane 352.

It will be noted that in order to properly remove Opaque uids from space 342between window 352'and the. shield 314, piston 178 of the hydraulic cylinder 38 is actuated by means of the above noted cycle timer to a point say about 2 inches below the top of the cylinder. At'this position of the piston it will be seen that the upper end of shield 314 is just below its closed position, leaving a relatively small opening between the top of the shield 314'and the adjacent end of body shell 320. The piston can then be reciprocated up and down over a distance of about l inch to force jets o-fwashingl fluid. through bores 354 downwardly into the top ofVi space 342 and resulting in. a washing of the window' lic cylinder 38, permitting the shield 314 to assume its:

completely closed positionY asv shown in Fig. 26, and

entrapping a substantially clear: brubble of liquid within: spacez342. Under these conditions'rthe too-l can be againv raised or, lowered: to any position in the well bore. at which it is desired to view theside of the bore, and the hydraulic piston 178 actuated downwardlyfto retract the shield 314 for viewing/the side ofthe bore through the clear bubble of. washing fluide in space 342.

The embodiment shown in. Fig. 2.6- can be further modified ifV desiredA to permit the washing iluid to be introduced intothe bottom. of space 342 instead of into the top. thereof via bores 354, as shown in Fig. 26. This can-beV accomplished by closing olf bores 354, and by connecting bore 68A withaplurality of bores passing downwardly throughthe retainer cylinder. 321B'and thence throughthe longitudinally extending segments 341). and 341 (see. Fig. 27) positioned across the window 352, and thence further-conducting the fluid-from the bottom of such bores through cylinder-320 adjacent the bottom of space 342 and communicating with the bottom of space 342. In thisfmanner', washing fluid will be dis charged in the form of jets upwardly from the bottom of space 342, forcing the opaque fluid in said space upwardly into the topof space 342 and out of the opening provided between the upper end of shield 314 and the adjacent lower end of retainer cylinder 32d, when the shield 314 is in retracted or partially retracted position. Simultaneously with this action, the motion of the washing uid passing upwardly in the space 342.

adjacent the window 352 will wash the surface of the window free ofany opaque particles depositedv thereon. From the foregoing, it is seen that there is provided;

according to-the invention, a tool which enables remote;

instantaneousviewing of a well bore or `casing to. obtain a quick, exact picture of the bore'or the side walls there-v of at any depth of the bore hole. The tool can be operated for long periods in the. well, and numerous areas of the bore viewed without the necessity of withdrawing the Idevice numerous times, e.g. to remove camera film from the cameravand reload it, a disadvantage of those known devices employing such camera means. The invention tool preferably embodies a commercially available closed circuit transmitting and receiving television system adapted for use in the device hereof and under the conditions encountered in well bores. A protective lens system is provided to enable scanning of the well bore while protecting the television system from contamination with well boreuids. The protective lens can be washed by a hydraulic washing system actuated from thewell surface, and the protective lens protected from deposition thereon of opaque substances contained in well bore fluids through which the tool passes, by means such as a diaphragm or other type closure, also actuable from a remote point at the surface of the well. Means for eicient lighting of the well bore is also provlded, as is means for cooling the television system to permit proper operation thereof 'at the high temperatures encountered in well bores. The device is compact and rugged, yet reliable in operation despite the employment of sensitive electronic components contained in the tele- Vision system.

While we have shown and described above the use of camera means in conjunction with a television system for pictorially viewing the interior of a well bore at al .statlon at the surface of the well while the tool is still.: 1n the well4 bore, and this is vour preferred embodiment,

it will be understood that camera means other than a television camera can be employed in combination with the other features of our device. Thus, a still or movie camera containing photographic film can be used with electric leads connected through cable 44 between the camera and a control mechanism at the surface, for operating the shutter and camera drive from the surface of the well. The types of cameras which can be employed for our purpose can be readily chosen by those skilled in this art.

While we have described a particular embodiment of our invention for the purpose of illustration, it should be understood that various modiiications and adaptations thereof may be made within the spirit of the invention as set forth in the appended claims.

We claim:

l. A bore hole inspection tool which comprises a case containing therein camera means, a protective lens for said camera means, a closure spaced from said protective lens away from said camera means, means for actuating said closure to open and close the same repeatedly during traverse of the tool in a well bore, said closure in its closed position forming a confined chamber located between said closure and said protective lens in said case, a receptacle adapted to contain a fluid, conduit means for conducting said fluid to said chamber, means for forcing said uid from said receptacle through said conduit means to said chamber, and means for raising and lowering said case in a bore hole.

2. A bore hole inspection tool which comprises a case containing therein a television camera, a closed circuit television system for viewing an image received by said camera, a protective lens for said camera, said lens having a diameter substantially equal to the inner dimeter of said case and closing off the interior of said case above said lens, a closure spaced from said protective lens away from said camera, means for actuating said closure to open and close the same repeatedly during traverse of the tool in a well bore, said closure in its closed position forming a coniined chamber located between said closure and said protective lens in said case, a receptacle adapted to contain a liuid, conduit means for conducting said uid to said chamber, means for forcing said fluid from said receptacle through said conduit means to said chamber, and means for raising and lowering said case in a bore hole.

3. A bore hole inspection tool which comprises a case containing therein a television camera, a closed circuit television system for viewing an image received by said camera, said camera and television system being positioned in a housing in said case, means for cooling said housing and the contents thereof, said cooling means including a container positioned in the space between said housing and said case, said container including a cooling medium, a protective lens for said camera, a closure spaced from said protective lens away from said camera, means for actuating `said closure to open and close the same repeatedly during traverse of the tool in a well bore, said closure in its closed position forming a confined chamber located between said closure and said protective lens in said case, a receptacle adapted to contain a 'washing fluid, conduit means for conducting said fluid to `said chamber, means for forcing said fluid from said receptacle through said conduit means to said chamber, and means for raising and lowering said case in a bore hole.

4. A bore hole inspection tool which comprises an elongated case, said case including a housing mounted near the lower end of said case, camera means positioned in said housing, a protective lens, mounted below said camera means in said case and closing oif a substantial portion of the interior of said case above said lens, a flexible diaphragm connected to the lower end of said case below said protective lens, said diaphragm being spaced from said lens, a reservoir in said case adapted i@ to contain a liquid, means for opening and closing said' diaphragm repeatedly during traverse of the tool in a well bore, said means including means for conducting liquid under pressure from said reservoir to said diaphragm and expanding said diaphragm to close olf the bottom of said case and means to withdraw said liquid into said reservoir to contract said diaphragm, means to conduct liquid from within said case into the space directly in front of said protective lens, means preventing return ow of liquid from said space into said case, and means for raising and lowering said case in a bore hole.

5. A bore hole inspection tool which comprises any elongated case, said case including a housing mounted near the lower end of said case, camera means positioned in said housing, a protective lens mounted below said camera means in said case and closing off a substantial portion of the interior of said case above said lens, a flexible diaphragm connected to the lower end of said case below Isaid protective lens, said diaphragm being spaced from said lens, a hydraulic chamber positioned in the closed oi interior portion of said case above said housing, a piston in said chamber, a first conduit connecting a portion of said hydraulic chamber on one side of said piston with said diaphragm for conducting liquid under pressure to said diaphragm and expanding said diaphragm to close off the bottom of said case, said liquid returning to said portion of said chamber, a second conduit connecting another portion of said hydraulic chamber on the other side of said piston With the space directly in front of said protective lens to direct fluid into said space for washing said protective lens, valve means in said second conduit preventing return flow of uid therein from the discharge end of said second conduit back to said hydraulic chamber, means for actuating said piston, and means for raising and lowering said case in a bore hole.

6. A bore hole inspection tool which comprises an elongated case, said case including a first housing mounted near the lower end of said case, said housing being spaced from the inner wall of said case, camera means positioned in said iirst housing, a container positioned in the annular space between said first housing and said case, said container including a cooling medium to cool said iirst housing and the contents thereof, a protective lens mounted below said camera in said case and closing off a substantial portion of the interior of said case above said lens, a lamp housing positioned adjacent said iirst housing and above said protective lens, a lamp in said lamp housing, said lamp being adapted to transmit light through said lens, a liexible diaphragm connected to the lower end of said case below said protective lens, said diaphragm being spaced from said lens, a reservoir in said case adapted to contain a liquid, means for opening and closing said diaphragm repeatedly during traverse of the tool in a well bore, said means including means for conducting liquid under pressure from said reservoir to said diaphragm and expanding said diaphragm to close off the bottom of said case and to withdraw liquid into said case to contract said diaphragm, and means for raising and lowering said case in a bore hole.

7. A bore hole inspection tool which comprises an elongated case, said case including a iirst housing mounted near the lower end of said case, said housing being spaced from the inner wall of said case, a television camera and a closed television circuit connected to said camera, said camera and circuit being positioned in said first housing, a container positioned in the annular space between said first housing and said case, said container including a cooling medium to cool said first housing and the contents thereof, a protective lens mounted below said camera in said case and closing off a substantial portion of the interior of said case above said lens, a lamp housing positioned adjacent said first housing and above said protective lens, a ring shaped lamp in said lamp housing, said lamp being adapted to transmit light through said lens, a flexible diaphragm connected to the lower end of said case below said protective lens, said diaphragm being spaced from said lens a reservoir in said case adapted to contain a liquid, means for opening and closing said diaphragm repeatedly during traverse of `the tool in a well bore, said means including means for conducting liquid under pressure from said reservoir to said diaphragm and expanding said :diaphragm to close off the bottom of said reservoir and means to withdraw liquid into said case to contract said diaphragm, means tok conduct' liquid from within said case into the space directly in front of said protective lens, means preventing return flow of liquid from -said space into said case, and means for raising and lowering said case in a bore hole.

8. A bore hole inspection tool which comprises an elongated case, said case including a first housing mounted near the lower end of said case, said housing being spaced from the inner wall of said case, a television camera and a closed television circuit connected to said camera, said" camera and circuit being positioned in said first housing, a container positioned in the annular space between said first housing and said case, said container including a cooling medium to cool said first housing and the contents thereof, a protective lens mounted below said camera in said case and closing off a substantial portion -of the interior of said case above said lens, a lamp housingl positioned adjacent said first housing and above said protective lens, a lamp in said lamp housing, said lamp being adapted to transmit light through said lens, a flexible Idiaphragm connected tothe lower end of said case below said protective lens, said diaphragm being spaced from said lens, a hydraulic chamber positioned in the closed off interior portion of said case above said first housing, a piston in said chamber, a first conduit connecting a portion of said hydraulic chamber on one side of said piston with said diaphragm, for conducting liquid under pressureA to said diaphragm and expanding said diaphragm to close olf the bottom of said case, said liquid returning to said portion of said charnber, a second conduit connecting another portion of said i hydraulic chamber on the other side of said piston with the space directly infront of said protective lens to direct liquid into said space for washing said protective lens, valve means in said second conduit preventing return flow of liquid therein from the discharge end of said second conduit back to said hydraulic chamber, means for actuating said piston, and means for raising and loweringv said case in a bore hole.

9. A bore hole inspection tool which comprises an elongatedV case, said case including a first housing mounted near the lower end of said case, a camera positioned in said first housing, aA protective lens mounted below said camera insaid case, and closing off a substantial portion of the interior of said case above said lens, said lens being composed of a central downwardly flared truncated conical' inner portion and an annular outer portion mating with said inner portion, an opaque coating at the interface between said inner and outer lens portions, said camera being in axial alignment with and receiving light substantially only from the central inner portion of said lens, a lamp housing positioned adjacent said first housing and above said protective lens, an annularly shaped lamp in said lamp housing, said lamp being in alignment with the outer portion of said lens and transmitting light substantially only through said outer lens portion, and means for raising and lowering said case in a bore hole.

l0. A bore hole inspection tool which comprises an elongated case, said case including a iirst housing mounted near the lower end of said case, said housing being spaced from the inner wall of said case, a television camera and a closed television circuit connected to said camera, said camera and circuit being Vpositioned in said first housing, a container positioned in the annular space between said first housing and said case, said container 18 including a cooling medium to cool said first housing and the contents thereof, a protective lens mounted below said camera in said case and closing off aA substantial portion of the interior of said Case above said lens, said lens being composed of a central downwardly flared truncated conical inner portion and an annular outer portion mating with said inner portion, an opaque Coating at the interface between said inner and outer lens portions, said camera being in axial alignment with and receivinglight substantially only from the central inner portion of said lens, a lamp housing positionedv adjacent said first housing and above said protective lens, an annularly shaped lamp in said lamp housing, said lamp being in alignment with. the outer portion of Said lens and transmitting light substantially only through said outer len'srpor'tion, and means for raising and lowering said case in` a bore hole'.

ll. A bore hole inspection tool which comprises an elongated case, said case including a rst housing mounted near the lower end of said case, said housing being spaced from the inner wall of said case, camera means positioned in said first housing, a container positioned in the annular space between said first housing and said case, said container including a cooling medium to cool said iirst housing and the contents thereof, a protective lens mounted below said camera in said case and closing 01T a substantial portion of the interior of said case above said lens, said lens being composed of a central downwardly flared truncated conical inner portion and an annular outer portion mating with said inner portion, an opaque coating at the interface between said inner and outer lens portions, said camera means being in 4axial alignment `with and receiving lightsubstantially only from the central inner portion of said lens, a lamp housing positioned adjacent said first housing and above said protective lens, an annularly shaped lamp in said lamp housing, said lamp being in alignment with the outer portion of said lens and transmitting light substantially only through said outer lens portion,` a flexible diaphragm con nected to the lower end of said case below said protective lens, said diaphragm being spaced from said lens, means for opening and closing said diaphragm, said means including means for conducting liquid under pressure from said case to said diaphragm and expanding said diaphragm to close off the bottom of said case andi'to withdraw said liquid into said case to contract said diaphragm, means to conduit a iluid from said case into the space directly in front of said protective lens, means preventing return flow of fluid from said space into said case, and means for raising and lowering said case in a bore hole.

V12. A bore hole inspection tool which comprises an elongated case, said case including a first housing mounted near the lower end of said case, said housing being spaced from the inner wall of said case, a television camera and a closed television circuit connected to said camera, said camera and circuit being positioned in said first i housing, a container positioned in the annular space between said first housing and said case, said container including a cooling medium to cool said first housing and the contents thereof, a protective lens mounted below said camera in said case and closing off a substantial portion of the interior of said case above said lens, said lens being composed of a central downwardly liared' truncated conical inner portion and an annular outer portion mating with said inner portion, an opaque coatinggat the interface between said inner and outer lens portions, said f camera being in axial alignment with and receiving light substantially only from the central inner portion of said lens, a lamp housing positioned adjacent said first housing "and above said protective lens, an annularly shaped lamp in said lamp housing, said lamp being in alignment with the outer portion of said lens and transmitting light' substantially only through said outer lens portion, a ilexible diaphragm connected to the lower end of said case below said protective lens, said diaphragm being spacedL 

